Reticle transport apparatus, exposure apparatus, reticle transport method, and reticle processing method

ABSTRACT

A reticle transport apparatus transports a reticle to and from a processing atmosphere. A reticle loader loads the reticle into the processing atmosphere, with at least a portion of the reticle being covered by a cover. A cover manipulator, in the processing atmosphere, removes the reticle from the cover and transfers the cover, without the removed reticle, to the reticle loader, and the reticle loader unloads the cover from the processing atmosphere. A cover cleaner, outside of the processing atmosphere, cleans the cover. When processing involving the reticle is completed, the reticle is returned to the cleaned cover or is placed in a different cover.

This application claims priority to U.S. Provisional Patent ApplicationNo. 60/853,450, filed on Oct. 23, 2006, the contents of which areincorporated herein by reference. This application also claims priorityto Japanese Patent Application No. 2005-377668, filed on Dec. 28, 2005,the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

A. Field of the Invention

The present invention relates to a reticle transport apparatus fortransporting a reticle with respect to an exposure atmosphere chamber,an exposure apparatus comprising the reticle transport apparatus, areticle transport method, and a reticle processing method.

B. Description of the Related Art

Recently developed projection exposure apparatuses expose the pattern ofa reticle onto a photosensitive substrate using extreme ultraviolet(EUV) light in the range of wavelengths of approximately 5˜40 nm. InEUVL (extreme ultraviolet light lithography) exposure apparatuses,because EUV light is absorbed by air, a high degree of vacuum ismaintained within the chamber that accommodates the apparatus, andspecial contrivances are also necessary when transporting the reticle.

A reflecting type reticle is typically used in the EUVL exposureapparatus, because few materials have a high transmittivity with respectto short wavelength light. A transparent thin film called a pellicle mayprotect the pattern surface of a reticle used in an exposure apparatusthat uses normal visible light or ultraviolet rays. However, in the EUVexposure apparatus, it is not possible to form a pellicle, because thereare few materials that have high transmittivity with respect to shortwavelength light. Therefore, at the time of reticle transport andstorage, the reticle is covered within a protective cover (protectivemember), and the pattern region of the reticle is protected (see U.S.Pat. No. 6,239,863).

While the reticle is protected within the protective cover andtransported, the reticle and the protective cover may come into contact,and debris may be generated at that contact point. Foreign matter thathas occurred due to the generation of debris may thus accumulate, andthe pattern region of the reticle may be contaminated.

SUMMARY OF THE INVENTION

In one embodiment of the present invention, a reticle transportapparatus prevents foreign matter from adhering to the reticle.

Additional objects and advantages of the invention will be set forth inpart in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention will be realized and attained bymeans of the elements and combinations particularly pointed out in theappended claims.

To achieve the objects and in accordance with the purpose of theinvention, as embodied and broadly described herein, a reticle transportapparatus transports a reticle to and from a processing atmosphere. Areticle loader loads the reticle into the processing atmosphere, with atleast a portion of the reticle being covered by a cover. A covermanipulator, in the processing atmosphere, removes the reticle from thecover and transfers the cover, without the removed reticle, to thereticle loader for unloading the cover from the processing atmosphere. Acover cleaner, outside of the processing atmosphere, cleans the cover.

To further achieve the objects and in accordance with the purpose of theinvention, as embodied and broadly described herein, a reticle transportmethod transports a reticle to and from a processing atmosphere. Themethod includes the steps of: loading the reticle into the processingatmosphere, at least a portion of the reticle being covered by a cover;detaching the cover from the reticle in the processing atmosphere; andunloading the detached cover from the processing atmosphere. The methodmay further include the step of cleaning the cover.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description, serve to explain the principles of theinvention.

FIG. 1 is a schematic diagram of an exposure apparatus.

FIG. 2 shows a protective cover for a reticle.

FIG. 3 shows an exploded view of the protective cover of FIG. 2.

FIG. 4 is a plan view of a reticle.

FIG. 5 is a partially schematic view of the protective cover of FIG. 2in a prealignment chamber.

FIG. 6 is a schematic view of an EUV exposure device.

FIG. 7 is a flow chart of a reticle loading process.

FIG. 8 is a schematic diagram of an exposure apparatus.

FIG. 9 is a flow chart a microdevice manufacturing process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

A reticle transport apparatus transports a reticle into and out of aprocessing atmosphere chamber. A reticle loader loads the reticle intothe processing atmosphere chamber. At least a portion of the reticle iscovered by a cover. A cover unloader unloads the cover, which isdetached from the reticle, from the processing atmosphere chamber. Acover cleaner cleans the unloaded cover.

The reticle transport apparatus removes foreign matter adhered to thecover. In particular, the cover cleaner cleans the cover for covering atleast the region of the reticle where a pattern is formed. Therefore, itis possible to prevent foreign matter from adhering to the reticle,while the reticle is covered by the cover. This improves exposureperformance.

In addition, the cover may be removed from the exposure atmospherechamber while the reticle is within the exposure atmosphere chamber. Thecover covering at least a portion of the reticle is detached from thereticle. Therefore, the cover may be inspected to determine whether ornot debris is adhering to the cover. The cover may also be cleaned orreplaced. Therefore, it is possible to prevent foreign matter fromtransferring to and adhering to the reticle.

In addition, if the reticle is covered with a new cover, a contaminatedcover may be discarded or cleaned.

The exposure apparatus relating to a first embodiment of the presentinvention will be explained while referring to drawings. FIG. 1 shows aschematic configuration of the exposure apparatus relating to the firstembodiment. An exposure part 3 may expose a pattern formed on a reticleonto a photosensitive substrate. A reticle transport part (reticletransport apparatus) 4 loads and unloads the reticle into and out of theexposure part 3 via a load lock chamber 12. A control part 26 controlsthe operation of the exposure apparatus and preferably includes aprogrammable processor such as a microprocessor.

In the reticle transport part 4, an air reticle library 6 holds aplurality of reticles on which various patterns are formed. An air siderobot 8 loads the prescribed reticle from the air reticle library 6 andtransports the reticle to the load lock chamber 12. A cleaning chamber10 cleans a protective cover that covers the reticle. The air reticlelibrary 6 accommodates reticles that are covered by a protective cover.The surfaces of the reticles on which a pattern is formed are covered bya protective cover prepared to respectively correspond thereto.

FIG. 2 shows a protective cover 2 that covers a reticle 1, and FIG. 3 isan exploded view for explaining the configuration of the protectivecover 2. The protective cover 2 includes an upper cover 2 a and a lowercover 2 b. The upper cover 2 a, preferably formed of a metal such asaluminum, for example, has a filter 2 c and a transparent window 2 d.The filter 2 c promotes an adequate air flow, while preventing fineparticles such as debris from penetrating to the interior of theprotective cover 2. The protective cover 2 goes back and forth betweenambient air and vacuum. When the upper cover 2 a and the lower cover 2 bof the protective cover 2 are engaged to form an interior space, the airpressure difference between the exterior and interior space of theprotective cover 2 is reduced so that force resulting from the pressuredifference is not exerted on the upper cover 2 a and the lower cover 2b. The transparent window 2 d is for observing the status of the reticle1 from outside the protective cover 2.

Two protruding parts 2 e, provided on the upper cover 2 a at twolocations, catch on a holding member and are held. The lower cover 2 bis lowered, and the upper cover 2 a and the lower cover 2 b areseparated. The upper cover 2 a includes two position detection marks 2 ffor detecting the position thereof. The position of the upper cover 2 amay be detected by measuring this position using a position measurementapparatus.

The lower cover 2 b, preferably formed of a metal such as aluminum, forexample, has positioning pins 2 g in pairs of two in the four cornersand reticle holding protrusions 2 h in three locations. The positioningpins 2 g position the reticle 1 in the planar direction when holding thereticle 1. The reticle holding protrusions 2 h support the reticle 1 atthree points.

Two transparent windows 2 i, 2 j, preferably made of glass, are providedon the lower cover 2 b, and marks and ID marks formed on the reticle 1are observed through the transparent windows 2 i, 2 j from the lowerside of the lower cover 2 b. FIG. 3 shows transparent windows 2 i, 2 j,but if the positions of the marks and ID marks are fixed on the reticle1, only one transparent window may be needed. The reticle 1,accommodated in the protective cover 2, is put into the air reticlelibrary 6.

FIG. 4 shows a plan view of one example of a pattern surface of thereticle 1 from the lower side. On the pattern surface of the reticle 1,a pattern such as a semiconductor circuit to be transferred onto a waferis formed in a central pattern region 24. A non-reflection region 22,such as an absorbing body, surrounds the pattern region 24. Referencereflecting surfaces 21 are outside of the non-reflecting region 22.Alignment marks and ID marks are formed in a mark region 23.

The protective cover 2 preferably covers at least pattern region 24 ofthe reticle 1. The protective cover 2 preferably protects the reticle 1from problems such as adherence of debris by covering the entire patternsurface of the reticle 1 as well as the entire reticle 1. In the presentembodiment, the protective cover 2 covers the entire reticle 1 using anupper cover 2 a and a lower cover 2 b. It is also possible to use aprotective cover such as the protective cover disclosed in U.S. Pat. No.6,239,863. The protective cover may protect only the pattern surface ofthe reticle 1, or the protective cover may protect only the patternregion of the reticle 1. In addition, the present invention may be usedeven if it is other than these reticle covers, and it may be applied toa reticle cover that covers only a portion of the reticle.

In the exposure apparatus, the load lock chamber 12 receives the reticle1 from the reticle transport part 4. A prealignment chamber 14pre-aligns the reticle 1. A vacuum side robot 16 transports the reticle1 and the protective cover 2 between the load lock chamber 12 and theprealignment chamber 14. The exposure part 3, the prealignment chamber14, and the vacuum side robot 16 are all within a vacuum atmospherechamber (exposure atmosphere chamber, processing atmosphere chamber). Inaddition, the load lock chamber 12 is configured for vacuum exhaust andair release.

FIG. 5 shows the prealignment chamber 14. A CFP opener 25 separates theprotective cover 2 into the upper cover 2 a and the lower cover 2 b. Thereticle 1 is on the lower cover 2 b. The CFP opener 25 is a one-levelrack having vertical plates 25 a and a horizontal plate 25 b (the othervertical plate 25 a is omitted from the drawing). The protruding parts 2e of the upper cover 2 a catch onto the horizontal plate 25 b, and theupper plate 2 a is suspended.

The protective cover 2 is lowered from above the horizontal plate 25 b.The front end part of the vacuum side robot 16 supports the lowersurface of the lower cover 2 b. The protruding parts 2 e of the uppercover 2 a catch on the horizontal plate 25 b, and the vacuum side robot16 is lowered. The lower cover 2 b and the reticle 1 that is loadedthereupon then drop downward. The upper cover 2 a, however, remains heldon the horizontal plate 25 b, because the protrusion parts 2 e catch onthe horizontal plate 25 b. The upper cover 2 a thus separates from thelower cover 2 b and the reticle 1. Then, the reticle 1, mounted on thelower cover 2 b, may be extracted by pulling the vacuum side robot 16 inthe direction of the arrow.

An alignment stage 22 may be provided on the CFP opener 25. Thealignment stage 22 moves in the X direction, as shown in the drawing,moves in the Y direction perpendicular to the X direction, and rotates(θ) around a Z direction axis, which is perpendicular to the X directionand the Y direction. In this example, the horizontal plate 25 b ontowhich the upper cover 2 a is mounted is fixed, but it is also possibleto provide a drive means to move it and adjust the position of the uppercover.

The position of the reticle 1 may be pre-aligned. The vacuum side robot16 is lowered, while the front end part of the vacuum side robot 16holds the lower cover 2 b, on which the reticle 1 is mounted. The lowercover 2 b is thus mounted on the alignment stage 22. The center part ofthe alignment stage 22 preferably has a protruding shape, so that thevacuum side robot 16 can be lowered to a position such that the frontend part of the vacuum side robot 16 does not come into contact with thelower cover 2 b. A through hole 22 a, provided at the center part of thealignment stage 22, enables detection of the position of the lower cover2 b and the position of the reticle 1 by a position detection apparatus.In addition, it is possible to perform prealignment of the reticle 1 bymoving the alignment stage 22.

In the exposure part 3, a reticle holder 18 holds the reticle 1 loadedby the vacuum side robot 16. The reticle holder 18 adsorbs the surfaceat the opposite side of the pattern surface of the reticle 1 shown inFIG. 4 by, for example, an electrostatic chuck. A light sourceilluminates the pattern of the reticle 1, and a projection opticalsystem projects the pattern onto a photosensitive substrate. Thephotosensitive substrate is thus exposed to the pattern of the reticle.

FIG. 6 is an outline diagram showing an EUV exposure device. EUV light32 emitted from an EUV light source 311 enters an illumination opticalsystem 33, becomes an approximately parallel light beam by a concavereflecting mirror 34 which acts as a collimator, and enters an opticalintegrator 35 comprising a pair of a fly-eye mirrors 35 a and 35 b. Asthe pair of fly-eye mirrors 35 a and 35 b, the fly-eye mirrors disclosedin U.S. Pat. No. 6,452,661, the contents of which are incorporatedherein by reference, may be used.

In the vicinity of the reflection plane of the second fly-eye mirror 35b, namely in the vicinity of the exit plane of the optical integrator35, a substantial extended light source having a specific shape isformed. Light from the substantial extended light source is deflected bya plane reflecting mirror 36, and forms an arc shaped illumination areaon a reticle 1. Light from an illuminated pattern of the reticle 1 formsan image of the reticle pattern on a wafer W by a projection opticalsystem PL comprising multiple reflecting mirrors (six reflecting mirrorsM1˜M6 are shown in FIG. 6 as an example). The reticle 1 is mounted on areticle stage 55 and can be moved in each of the x, y, and z axesdirections and rotated around each of the axes.

The wafer W is mounted on a wafer stage 56 and can be moved in each ofthe x, y, and z axes directions and rotated around each of these axes.Freedom of movement may also be fewer than this. The x and y directionpositions of the wafer stage and the reticle stage are measuredindependently by an interferometer, and the measured data are input to acontrol device 51. Also, the control device 51 outputs driving signals57 and 58 to the reticle stage 55 and the wafer stage 56. Each stagemoves by an actuator such as a linear motor or an air actuator.

A light source 52 emits light toward the wafer W, a photo-detector 54detects the light reflected from the wafer W to measure the position ofthe wafer W. Similarly, a light source 61 emits light toward the reticle1, and a photo-detector 62 detects the light reflected from the reticle1 to measure the position of the wafer W. The control device 51 receivesthe measured data.

Next, a reticle transport method that transports the reticle 1 into andout of the exposure part 3 by the reticle transport part 4 relating tothe first embodiment will be explained while referring to the flowchartin FIG. 7.

The reticle 1, which has been protected by the protective cover 2, isextracted from the air reticle library 6 and loaded into the load lockchamber 12 using the air side robot 8 (step S10).

After the reticle 1 that has been protected by the protective cover 2 instep S10 is loaded into the lock chamber 12, the load lock chamber 12 isexhausted for loading the reticle 1 into the vacuum atmosphere of theexposure part 3, and the interior of the load lock chamber 12 is madeinto a vacuum atmosphere (step S11). At this time, the interior of theprotective cover 2 also undergoes vacuum exhaust and becomes a vacuumatmosphere. Next, the vacuum side robot 16 extracts the reticle 1covered by the protective cover 2 from the load lock chamber 12 andloads it into the prealignment chamber 14. The reticle 1 is pre-aligned(step S12). At this time, the upper cover 2 a of the protective cover 2is removed.

Next, the vacuum side robot 16 is used to transfer the reticle 1 that iscovered by the lower cover 2 b of the protective cover 2 from theprealignment chamber 14. Then, the reticle 1 is moved to the reticleholder 18. The reticle 1 is adsorbed to the reticle holder 18 (stepS13), and the lower cover 2 b of the protective cover 2 is removed.Next, after the reticle 1 is adsorbed by the reticle holder 18 in stepS13, the vacuum side robot 16 unloads the protective cover 2, whichincludes the upper cover 2 a and the lower cover 2 b, from the exposurepart 3 (step S14: protective cover unloading process) and loads it intothe load lock chamber 12. Debris may fly about within the load lockchamber 12 when the atmosphere of the load lock chamber 12 changes fromvacuum to ambient air. Therefore, the upper cover 2 a and the lowercover 2 b may be closed during the unloading so that debris does notenter the interior space.

Next, after a protective cover 2 is loaded into the load lock chamber12, air release of the load lock chamber 12 is performed, and theinterior of the load lock chamber 12 changes to air atmosphere (stepS15). At this time, the interior of the protective cover 2 is also airreleased, and it is made an air atmosphere. The air side robot 8extracts the protective cover 2 from the load lock chamber 12 andtransports the protective cover 2 to the cleaning chamber 10, and theprotective cover 2 is cleaned (step S16: protective cover cleaningprocess).

The positioning pins 2 g and the reticle holding protrusions 2 h contactwith the reticle 1 when the reticle 1 is accommodated within theprotective cover 2. Dust generation may occur in the vicinity of thepositioning pins 2 g and the reticle holding protrusion 2 h. Any foreignmatter (debris) produced by this dust generation may adhere to thereticle holding protrusions 2 h and the reticle 1. The foreign mattermay accumulate on the protective cover 2 and the reticle 1 by repeatedunloading and loading of the reticle 1, and foreign matter may adhere tothe pattern region of the reticle 1, contaminating the pattern region ofthe reticle 1. In this way, due to the pattern region of the reticle 1being contaminated by foreign matter, it is not possible to accuratelyexpose the pattern of the reticle 1 onto the photosensitive substrate inthe exposure part 3. This leads to a reduction in the conformingproducts rate of the semiconductor devices manufactured. Therefore, itis necessary to remove any foreign matter produced by dust generated inthe vicinity of the positioning pins 2 g and the reticle holdingprotrusions 2 h.

Various well known cleaning methods can be used as the specific cleaningmethod in step S16. It is possible to use various cleaning methods suchas wet cleaning, dry cleaning, or cleaning in which wind is produced bya blower, etc. to blow foreign matter off. Essentially, any cleaningtechnique that removes substances such as liquid, solid bodies, etc.,that adversely affect exposure from the cover 2, can be used for thecleaning. For example, drying (baking) may be performed after performingultrasonic cleaning (cleaning for approximately 3 minutes in an Absolliquid+approximately 2 minutes in an alkali cleaningsolution+approximately 1 minute in pure water). After cleaning step S16,a particle counter, etc. may be used to confirm whether or not foreignmatter (debris) is adhering. If foreign matter is not adhering, cleaningends. If foreign matter is adhering, cleaning continues or is repeated.

Next, the air side robot 8 transfers the protective cover 2, for whichcleaning is completed, from the cleaning chamber 10 to the load lockchamber 12 (step S17). Next, after the protective cover 2 is reloadedinto the load lock chamber 12 in step S17, vacuum exhausting of the loadlock chamber 12 is performed, and the interior of the load lock chamber12 is made into a vacuum atmosphere (step S18). At this time, theinterior of the protective cover 2 is also vacuum exhausted, and itbecomes a vacuum atmosphere.

Next, the vacuum side robot 16 transfers the protective cover 2 from theload lock chamber 12 to the prealignment chamber 14. Then, theprotective cover stands by until the reticle 1 is unloaded from theexposure part 3 (step S19). When the reticle 1 is unloaded from theexposure part 3, the vacuum side robot 16 unloads the lower cover 2 bfrom the prealignment chamber 14, and the lower cover 2 b is loaded intothe exposure part 3. Then, the reticle 1, covered by the lower cover 2b, is carried to the prealignment chamber 14. The lower cover 2 b andthe upper cover 2 a are closed in the prealignment chamber 14, and thereticle 1 is accommodated within protective cover 2. The reticle 1, inthe protective cover 2, is unloaded to outside the vacuum atmospherechamber via the load lock chamber 12.

Through the exposure apparatus relating to the first embodiment, foreignmatter may be removed from a protective cover 2, because the cleaningchamber 10 cleans the protective cover 2. Therefore, the protectivecover 2 may be maintained in a clean status, and the adherence offoreign matter to the reticle 1 is restricted, so exposure performanceincreases. In particular, since it is possible to unload the protectivecover 2 to outside the vacuum atmosphere chamber in a status in whichthe reticle 1 is arranged within the clean atmosphere of the interior ofthe vacuum atmosphere chamber, the reticle 1 does not becomecontaminated when the protective cover 2 is cleaned.

In addition, the protective cover 2 is merely standing by while thereticle 1 is being used in exposure, so it is possible to use this idletime to clean the protective cover 2, so no adverse effects are exertedon the yield per unit time of the device to be manufactured.

In the first embodiment, the reticle transport part includes a cleaningchamber for cleaning the protective cover, and cleaning of theprotective cover is performed in the reticle transport part, butcleaning of the protective cover at other locations may also beperformed in the case in which the reticle transport part does notcomprise a cleaning chamber.

In addition, in the first embodiment, protective covers are prepared torespectively correspond to the individual reticles, but one protectivecover may also be used to perform unloading and loading of a pluralityof reticles. Specifically, in the first embodiment, for protecting thereticle 1 unloaded from the exposure part 3, the cleaned protectivecover 2 stands by in the prealignment chamber 14. However, a differentreticle, loaded into the exposure part 3, may be protected by thecleaned protective cover 2.

In addition, in the first embodiment, exposure is performed as thereticle processing, but it is also possible to apply the presentinvention to other processing of the reticle.

Next, the exposure apparatus relating to a second embodiment will beexplained. FIG. 8 shows an exposure apparatus according to the secondembodiment. As shown in FIG. 8, the exposure apparatus according to thesecond embodiment includes a protective cover library 30 and a vacuumreticle library 31 in which reticles covered by a protective cover areable to stand by.

While a cleaning chamber 10 was arranged in the reticle transport part 4of FIG. 1, the protective cover library 30 is arranged in the reticletransport part 4′ of FIG. 8. A plurality of cleaned protective coversare arranged in the protective cover library 30. The protective cover 2,transported along with the reticle to a vacuum atmosphere via the loadlock chamber 12, is separated from the reticle. After that, only theprotective cover 2 is unloaded to the standby side via the load lockchamber 12. Processes up to this point are similar to those of the firstembodiment.

In the second embodiment, instead of cleaning the protective cover 2, adifferent protective cover arranged in the protective cover library 30is used. Specifically, a separate protective cover arranged in theprotective cover library 30 is loaded into the interior of the vacuumatmosphere via the load lock chamber, and the reticle 1 is covered afterexposure processing has ended. The reticle 1, covered by the protectivecover, may standby in the vacuum reticle library 31, and it may beunloaded to the air side as-is. When this is done, a cleaning chamber 10need not be arranged beside the exposure apparatus. This reduces thefootprint of the exposure apparatus. In addition, since it is possibleto use a cleaned protective cover, it is possible to preventcontamination of the reticle.

If ID information related to the reticle, etc. is assigned to theprotective cover 2, an ID information rewriter may be included in theprotective cover library 30 or at another location. For such rewriting,it is possible to use various well known techniques according to thetype of ID information. For example, it is possible to mechanicallyreplace an ID consisting of a barcode or to use software to rewrite IDinformation. The ID information may be read by an ID reader.

In the first and second embodiments, transport apparatuses 4, 4′ arearranged beside the load lock chamber 12. Instead of this, for example,it is possible to transport the reticle using an Automated Guidedvehicle with robot, and it is possible to use a configuration in whichall or part of the transport apparatus 4, 4′ is not arranged beside theexposure apparatus. In this case, it is possible to share the airreticle library 6, the cleaning chamber 10, or the protective coverlibrary 30 among a plurality of exposure apparatuses. When this is done,the footprint of the exposure apparatus in the clean room may bereduced.

In the first and second embodiments, the protective cover is cleaned orreplaced each time the reticle and the protective cover separate, butthis can be set to any timing. For example, this timing may be decidedbased on the number of times that the reticle cover is used (it ispossible to use the count of the number of times of attachment to thereticle or the number of times, etc. carried in from the air to vacuumas the number of times used) or the usage time, etc.

For example, a user may input the replacement timing directly from akeyboard and store it in a storage part arranged within the control part26. Replacement or cleaning commands may be output from the control part26 based on this stored data. The storage part may be arrangedseparately from the control part 26. In addition, a user may send datavia a network to the storage part. In addition, data may be recorded inadvance to a variety of recording media such as optical disks, magneticdisks, USB memories, etc. The recording media may be connected to theexposure apparatus to transfer replacement or cleaning timing to thestorage part 26. Data such as the number of times, the time, etc. may bedirectly taken in as timing data, but it is also possible to input otherparameters for computing these data to obtain and use the number oftimes or the time by means of calculations by the control part 26.

A debris detection apparatus may detect the presence or absence ofdebris at the reticle holding protrusions 2 h that connect with thereticle, the positioning pins 2 g, or the periphery thereof. Replacementor cleaning may be performed based on the debris detection results. Forexample, the replacement or cleaning timing may be upon cases whereforeign matter is present or upon cases where the amount of foreignmatter has exceeded a threshold value.

As shown in FIG. 5, an optical system debris detection apparatus 50 hasa light source 51 and a detector 52. The detector 52 detects light thathas emerged from the light source 51 and has been reflected by thereticle cover. When foreign matter is present, the foreign matterscatters light and the intensity of the light detected by the detector52 changes. It is possible to detect the presence or absence of foreignmatter from these changes. Any type of apparatus may be used as theforeign matter detection apparatus, as long as it is able to detect thedesired foreign matter. A commercially available particle counter may beused. In the example shown in FIG. 5, foreign matter is detected in theprealignment chamber 14, but it may be detected at other locations. Forexample, such a foreign matter detection mechanism may be arranged inthe vacuum reticle library 31 to perform foreign matter detection as inthe application example shown in FIG. 8.

An ID mark that indicates distinguishing characteristics related to thereticle cover (the mark may be secured to the cover or removablyarranged, and the mark may be a rewritable mark) may be associated withthe ID of the reticle and controlled. The reticle cover is storedoutside the exposure apparatus, while the reticle is in the exposureapparatus. The ID of the reticle cover, however, identifies the type ofreticle. The ID may be read by machine, or it may be directly read by anoperator. Of course, in the case where it is possible to directlyconfirm the type of reticle by means of the reticle cover itself beingtransparent or a window being provided in the reticle cover, suchassociation need not be performed. In addition, it is also possible toaccommodate the reticle cover inside a reticle SMIF pod (RSP) andcontrol the reticle based on an ID mark assigned to the RSP.

Where the ID of the reticle and the ID of the reticle cover areassociated to perform control, when replacement of the reticle cover isperformed while in progress as discussed above, it is preferable thatthe ID of the new reticle cover and the ID of the reticle accommodatedtherein be associated again or that the ID of the new reticle cover berewritten or replaced.

It is preferable that the reticle covers be controlled so that ID of thereticle cover is stored and a determination is made as to which reticlecover from among the plurality of reticle covers that are present is tobe replaced or cleaned. When this is done, it is possible toindependently determine the replacement or cleaning times of therespective reticle covers even if a plurality of reticle covers arepresent.

In the embodiments discussed above, the explanations used exposureprocessing as an example of reticle processing, but, for example, thepresent invention may be applied to other processing performed on thereticle, such as the case in which the reticle is cleaned.

As has been explained, the embodiments use a reticle in a clean statusin which foreign matter is not adhering. In the exposure process, forexample, it is possible to perform the desired transfer, so it ispossible to reduce the defect rate of the devices to be manufactured.

As shown in FIG. 9, a microdevice, such as a semiconductor device, isproduced by performing, for example, a step S30 of designing thefunction and the performance of the microdevice, a step S32 of producinga mask (reticle) based on the designing step, a step S34 of producing asubstrate as a base material for the device, an exposure process stepS36 of exposing the substrate with a pattern of the reticle by using theexposure apparatus, a step S38 of assembling the device (includingprocessing steps such as a dicing step, a bonding step, and a packagingstep), and an inspection step S40. The exposure process step includesprocesses of cleaning or replacing the reticle cover during the waferexposure process.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1. A reticle transport apparatus that transports a reticle to and from aprocessing atmosphere, the reticle transport apparatus comprising: areticle loader for loading the reticle into the processing atmosphere,at least a portion of the reticle being covered by a cover; a covermanipulator, in the processing atmosphere, for removing the reticle fromthe cover and for transferring the cover without the removed reticle tothe reticle loader for unloading the cover from the processingatmosphere; and a cover cleaner, outside of the processing atmosphere,for cleaning the cover when the reticle is removed.
 2. A reticletransport apparatus according to claim 1, wherein the cover manipulatorinserts the reticle into a second cover different from the cover.
 3. Areticle transport apparatus according to claim 1, wherein the covermanipulator inserts the reticle into the cover after cleaning.
 4. Areticle transport apparatus according to claim 1, wherein the processingatmosphere is a vacuum atmosphere.
 5. A reticle transport apparatusdescribed in claim 1, further comprising a load lock chamber having aninner atmosphere, the inner atmosphere changing between the processingatmosphere and an ambient atmosphere, wherein the reticle loader loadsthe reticle into the processing atmosphere via the load lock chamber. 6.A reticle transport apparatus according to claim 1, wherein theprocessing atmosphere is an exposure atmosphere.
 7. A reticle transportapparatus according to claim 1, wherein the cover covers at least theregion where the pattern of the reticle is formed.
 8. A reticletransport apparatus according to claim 1, wherein the cover protects thereticle.
 9. An exposure apparatus that transfers a pattern formed on areticle to a photosensitive substrate; the exposure apparatus comprisingthe reticle transport apparatus according to claim
 1. 10. An exposureapparatus that transfers a pattern formed on a reticle arranged within aprocessing atmosphere to a photosensitive substrate, the exposureapparatus comprising: a reticle loader for loading the reticle into theprocessing atmosphere, at least a portion of the reticle being coveredby a cover; a cover detacher in the processing atmosphere for detachingthe cover from the reticle; and a cover unloader for unloading thedetached cover from the processing atmosphere, wherein after cleaning,the reticle loader loads the cover, without the reticle, into theprocessing atmosphere.
 11. An exposure apparatus according to claim 10,wherein the exposure atmosphere is a vacuum atmosphere.
 12. An exposureapparatus according to claim 10, wherein the cover covers at least theregion where the pattern of the reticle is formed.
 13. A reticletransport method for transporting a reticle to and from a processingatmosphere, the method comprising: loading the reticle into theprocessing atmosphere, at least a portion of the reticle being coveredby a cover; detaching the cover from the reticle in the processingatmosphere; unloading the detached cover from the processing atmosphere;and cleaning the cover when the reticle is removed.
 14. A reticletransport method for transporting a reticle to and from a processingatmosphere, the method comprising: loading the reticle into theprocessing atmosphere at least a portion of the reticle being covered bya cover; detaching the cover from the reticle in the processingatmosphere; unloading the detached cover from the processing atmosphere;and loading the cover, without the reticle, into the processingatmosphere after cleaning.
 15. An exposure method according to claim 14,wherein the cover covers at least the region where the pattern of thereticle is formed.
 16. A reticle processing method, comprising:transporting the reticle to a desired position, at least a portion ofthe reticle being covered with a first cover; detaching the first coverfrom the reticle; performing a desired processing on the reticle;covering the reticle with a second cover different from the first cover;and cleaning one of the first and second covers when the reticle isremoved.
 17. A reticle processing method according to claim 16, whereinthe desired processing includes exposure processing that irradiatesillumination light to the reticle and exposes and transfers a patternformed on the reticle onto a photosensitive substrate.
 18. A method ofmanufacturing a device according to claim 17, comprising: preparing asensitive substrate as a base material for the device exposing thesensitive substrate via the exposure processing.
 19. A reticleprocessing method according to claim 16, wherein detaching the firstcover occurs within a clean atmosphere.
 20. A reticle processing methodaccording to claim 16, wherein detaching the first cover occurs within avacuum atmosphere.
 21. An exposure apparatus according to claim 16,wherein the first cover covers at least the region on which the patternof the reticle is formed.